This invention relates to a composition of material for use as a friction material in a brake. This composition uses steel fiber as the reinforcing material. The steel fiber is combined with fillers, a lubricant, and friction modifiers which are held in a binder made up of rubber and phenolic resin. The resulting friction material has a substantially uniform and predictable coefficient of friction after repeated brake applications.
Many different fibers have been suggested as a substitute for asbestos in reinforcing a brake lining, for instance U.S. Pat. No. 3,967,037 discloses the use of glass fiber, U.S. Pat. No. 3,896,075 discloses the use of basalt fiber, U.S. Pat. No. 4,019,912 discloses the use of carbon fiber, and U.S. Pat. No. 4,119,591 discloses the use of a mixture of cellulose and steel fibers. Unfortunately such substitutions have resulted in some undesirable characteristics such as rotor wear, low temperature coefficient of friction stability, noise and high temperature structural unity.